Harvesting of seed crops is generally carried out on a commercial scale using a combine harvester to collect the crop heads and a portion of the straw or stalk and to separate the seeds from the remaining material for collection on the combine harvester.
In some cases the combine harvester includes a straight cut header which cuts the crop from its standing position in the field.
In other cases, it is desirable to separately and previously cut the crop from its standing position to form a lying swath of the crop which is left to dry in the swath condition before the crop from the swath is lifted into the combine using a pickup type header for separation of the seeds from the remaining crop materials.
Both the straight cut technique and the swathing technique have advantages in different crop conditions.
The same techniques are used in regard to crops in the genus Brassica which includes amongst others Canola, Mustard and Crambe. However it is also known that care has to be taken in the harvesting of these crops in that if they are left to stand in the field for an extended period of time, the crop is prone to shattering in which movement of the crop in the wind or other weather conditions causes pods to break open releasing the seeds from the crop to be deposited on the ground where they are lost to the harvesting process and can cause problems in later years. In many cases, therefore, the swathing technique is the method currently preferred.
Some experimental or research work has been carried out in Sweden in which small or research plots of this crop have used simple relatively crude techniques to flatten or lodge the crop. This has been done mainly to hold narrow swaths in place since narrow width swaths do not have sufficient bulk and tend to break up in any windy conditions. No publications describing this work are known.